Device for determining the rotation angle of a shaft in an aircraft

ABSTRACT

A device for determining the rotation angle of a shaft in an aircraft, the device having a shaft and a motor operable to rotate the shaft to operate a component and to detect first rotation data of the shaft. The device also includes a position pickup unit designed to detect second rotation data of the shaft, and a synchronization unit for synchronizing the first rotation data with the second rotation data.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation, of U.S. application Ser. No.11/358,529, filed on Feb. 21, 2006, which claims priority from U.S.Provisional Application No. 60/655,326 filed Feb. 23, 2005, all of whichare incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to determining the rotation angle of ashaft in an aircraft. In particular the present invention relates to adevice for determining the rotation angle of a shaft in an aircraft; toan aircraft comprising a corresponding device; to the use of acorresponding device in an aircraft; and to a method for determining therotation angle of a shaft in an aircraft.

The system for operating a brake flap or a landing flap or landing slatin an aircraft forms part of the safety-critical systems within theaircraft. Nowadays electromechanical systems for operating the landingflaps or landing slats are used, which systems are designed so as to beredundant if need be and have proven to be highly reliable. In order tooperate the landing flaps or landing slats, generally speakingmechanical shaft systems for transmission of the rotational forces areused. In order to prevent the occurrence of asymmetries in the flappositions and in order to still be able to adjust all the flaps should adrive motor fail, all flaps are connected to central shafting.

The position of the flaps is measured by way of two or even fourindependent position pickup units (PPUs) for each flap segment on theshaft. These sensors are located at the ends of the shaft part so as todetect differences in the absolute positions of the two shaft ends, andin this way provide information about the forces acting on themechanism. In the normal state the servo motors are highly synchronised,in other words no forces act on the shaft.

If, in the case of a malfunction, one of the PPUs fails, in the state ofthe art the motor that is seated on the corresponding shaft end isswitched off because it is no longer possible to measure the position,and because the motor would then not be synchronised. Possibly aso-called force fight between the two motors would develop, and at somestage the shaft would be destroyed. On the other hand this also meansthat a fault-free and properly functioning component (namely the motor)is switched off because of a malfunction of some other component so thatthe availability of the system may be thus reduced by 50%. Furthermore,the dynamics and agility of the system may be reduced by 50% because theremaining motor then runs only at half its possible rotary speed. Inorder to maintain synchronicity, the same also applies to the otherwing.

SUMMARY OF THE INVENTION

Amongst other things, it may be an object of the present invention to,state improved rotation angle determination in an aircraft.

According to one embodiment of the present invention the above objectmay be met by means of a device for determining the rotation angle of ashaft in an aircraft, wherein the device comprises a shaft and a motor,wherein the motor is designed to rotate the shaft, and wherein the motorfurthermore is designed to detect first rotation data in an absolutemanner which first data correspond to a rotation angle of a first regionof the shaft. The shaft may be designed for operating a device, selectedfrom the group consisting of brake flap, landing flap or landing slat,rudder, aileron and elevator. Moreover, the device for determining therotation angle of a shaft in an aircraft comprises a position pickupunit and a synchronisation unit, wherein the position pickup unit isdesigned to detect second rotation data, which data corresponds to arotation angle of a second region of the shaft, and wherein thesynchronisation unit is designed to synchronise the first rotation datawith the second rotation data.

Measuring the rotation data or rotation angles by means of a drive motorensures a simple and automatic rotation angle determination withouthaving to provide additional detection devices. This may be ensured byinstalling drive motors which automatically measure their currentpositions internally and with high precision during operation.

Because of the provision of the position pickup unit and the motordetecting rotation data, a redundant system may be provided whichmeasures rotation data even if, for example, one or all position pickupunit(s) should fail, because in this case the drive motor is stillavailable for measuring rotation data. This results in a significantincrease in the availability of the landing flap or landing slat orbrake flap system. Even if all PPUs should fail it is not necessary toswitch the motors off.

Because of the provision of the synchronisation unit it can be ensuredthat the zero points (in other words the positions of the first andsecond shaft regions at which rotation of the shaft regions has not yettaken place) of the position pickup unit and of the motor agree witheach other. For example, in flight calibration of the motors can takeplace based on the data provided by the position pickup unit.

Due to the fact, that the shaft is designed for operating a device,selected from the group consisting of brake flap, landing flap orlanding slat, rudder, aileron and elevator the control surfaces or flapsof the aircraft can be determined redundantly and in various ways (notonly by way of the motor control system, but also by way of thecorresponding position pickup units). Consequently, improved systemsafety or system availability of the control surface systems or flapsystems may be ensured.

According to a further embodiment of the present invention the devicefurther comprises a control unit, wherein the motor is designed totransmit the first rotation data to the control unit, and wherein thecontrol unit is designed to control or regulate the rotation data of theshaft on the basis of the transmitted first rotation data.

According to this embodiment of the present invention, the motor can forexample transmit the rotation angle of the first shaft region, whichrotation angle has been measured by said motor, by way of a databus or awireless connection or the like to the control unit, which is forexample housed in the fuselage. Consequently it may be ensured that theon-board control unit always receives the current rotation data of thefirst shaft region.

According to a further embodiment of the present invention the positionpickup unit is designed to transmit the second rotation data to thecontrol unit, wherein the control unit is designed to control orregulate the rotation of the shaft on the basis of the transmitted firstand second rotation data.

This may make it possible for the central control unit to always receivedata that represents the rotation angle of the first shaft region andthe rotation angle of the second shaft region. In this way the controlunit has at any point in time sufficient information relating to thepresent positions of the two shaft regions available. Thus, theredundant design of the rotation data measuring devices may ensureexcellent system safety.

According to a further embodiment of the present invention the controlunit for controlling or regulating the rotation of the shaft is designedonly on the basis of the transmitted first rotation data when thetransmitted second rotation data is faulty or incomplete.

Therefore, improved system availability may be ensured to the extentthat in the case of failure of all PPUs it is not necessary to switchthe motors off because there is still sufficient rotation data of theshaft available.

According to a further embodiment of the present invention the controlunit for controlling or regulating the rotation of the shaft is designedon the basis of the transmitted first and second rotation data, even ifthe transmitted second rotation data is faulty or incomplete.

According to this embodiment, for example, faulty or incomplete rotationdata of the position pickup unit can be supplemented on the basis of thesupplied rotation data of the motor so that in the final analysis acomplete data set is available again.

According to a further embodiment of the present invention a method fordetermining the rotation angle of a shaft in an aircraft is stated. Theshaft is rotated by a motor, and first rotation data that correspond tothe rotation angle of a first region of the shaft is detected by themotor in an absolute manner. Moreover, second rotation data thatcorresponds to a second rotation angle of a second region of the shaftis detected by a position pickup unit. Subsequently, the first rotationdata will be synchronised with the second rotation data.

According to this embodiment of the present invention a simple and quickmethod is stated in which rotation data of the shaft is automaticallydetected by way of its drive means, without there being a need toprovide additional detection devices. This can not only lead to savingsin cost and weight, but also to improved redundancy and therefore systemavailability.

Further embodiments of the present invention are stated in thesubordinate claims and in the further independent claims.

Below, with reference to the figures, preferred embodiments of thepresent invention are described.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows a diagrammatic perspective illustration of an aircraft witha device according to one exemplary embodiment of the present invention;

FIG. 2 shows a diagrammatic perspective illustration of a device fordetermining the rotation angle according to one exemplary embodiment ofthe present invention;

FIG. 3 shows a diagrammatic perspective detail of the device shown inFIG. 2; and

FIG. 4 shows a diagrammatic cross sectional illustration of a shaft foroperating a brake flap in an aircraft.

In the following description of the figures, the same referencecharacters are used for identical or similar elements.

DETAILED DESCRIPTION

FIG. 1 shows a diagrammatic perspective illustration of an aircraft witha device according to one embodiment of the present invention. As shownin FIG. 1, in both of its wings the aircraft 100 comprises a device 200according to the invention, which device 200 is for example provided foroperating the brake flaps or landing flaps or landing slats, or foroperation of the ailerons or the like.

The device 200 is also shown within a simulation model (not incorporatedin an aircraft) 300, which simulation model 300 is shown in detail inFIGS. 2 and 3.

The device 200 comprises a shaft 1, two motors 2, 3 and a brake 4.Furthermore, rotation actuators 7, 8, 9, 12 are provided which, as isalso the case with the motors 2, 3, make it possible to determinerotation data of the corresponding shaft sections.

The measuring data that is picked up by motors 2, 3 and actuators 7, 8,9, 12 is supplied by way of corresponding data lines (not shown inFIG. 1) to a central power control unit (PCU) 10. There the data can beevaluated, and corresponding control signals or regulating signals canbe made available to the flap motors or aileron motors.

FIG. 2 shows a diagrammatic perspective illustration of a device fordetermining the rotation angle according to one embodiment of thepresent invention. The device shown in FIG. 2, which device can forexample be integrated in an aircraft wing, in the case of FIG. 2 isinstalled in a simulation model 300. The device comprises a shaft 1,motors 2 and 3, a system brake 4, a load-simulation cylinder 5 andservos 6 to simulate a flap resistance, actuators or position pickupunits 7, 12, as well as a first shaft region 13 and a second shaftregion 14.

The end regions of the shaft 1 are rotated by way of the two motors 2, 3in order to operate the flaps or ailerons that are simulated by way ofthe cylinders 5 and servos 6. In this arrangement the rotation means ofthe corresponding shaft regions are measured by way of the actuators 7and 12, and the corresponding measuring data is transmitted to thecentral control unit 10 (see FIG. 1). Furthermore, the rotation data ofthe shaft region near the motors 2, 3 is detected directly by the motors(during operation) and is also transmitted to the central control unit10.

The motors used for adjusting the flaps measure the set positionsinternally with very high precision—much more precisely than is the casewith presently available PPUs 7, 12. In this arrangement measuring theposition data or rotation data takes place for example absolutely ratherthan incrementally. By way of corresponding data lines this positiondata is then transmitted to the control unit 10, rather than (as hasbeen the case up to now) remaining within the motor units.

If the PPU data and the motor position data are supplied to the controlunit 10, for example according to one embodiment of the presentinvention the motor position data can correspondingly be converted. Thiscan for example take place following a calibration procedure whichdetermines the zero point of the motor on the basis of the rotation dataprovided by the position pickup units 7, 12.

Consequently the rotation data measured by the motors 2, 3 is directlycomparable with the PPU data, and in the case of failure or malfunctionof a PPU, according to the invention the corresponding motor no longerneeds to be switched off since positioning data is still available atthe corresponding motor.

Furthermore, position data of a PPU, which furnishes data that is onlyslightly incorrect (bit hanger), can now be detected and evaluated orused accordingly, which has not been possible up to now.

According to one embodiment of the present invention the motor positiondata together with the data of the position pickup units 7, 12 istransmitted to the control unit 10 and every now and then issynchronised with the data from the position pickup unit. Consequentlyany motor drift that may occur can be calculated out.

If for example one of the PPUs 7, 12 fails, the rotation data orposition data of the corresponding drive motor 3, 2 continues to beavailable so that conclusive information about the position of thecorresponding shaft region and thus of any dynamic effect on the shaftcan continue to be obtained and the motor does not have to be switchedoff.

According to one embodiment of the present invention the rotation datameasured by the motors can be used to repair or supplement faulty orincompletely transmitted rotation data of the position pickup units 7,12. This takes place for example within the control unit 10. Even if allposition pickup units 7, 12 should fail, safe operation of the flapequipment or aileron equipment may still be ensured because there isstill sufficient rotation data in relation to the corresponding shafts1.

FIG. 3 shows a diagrammatic perspective detail of the device shown inFIG. 2. As shown in FIG. 3, the drive motor 2 is arranged on the end ofthe shaft 1 so as to rotate the shaft 1. The load cylinder 5 is used forsimulating the forces acting on the flaps or ailerons, which forces arefor example caused by air resistance.

By way of data lines and supply lines 15 it is for example possible totransmit rotation data measured by the motor 2 to the control unit 10 ofFIG. 1. Of course this data transfer can also take place by way ofadditional data lines or wirelessly.

FIG. 4 shows a diagrammatic cross sectional illustration of a shaft foroperating a brake flap. As shown in FIG. 4 the shaft 1 comprises a homeposition 41 that is for example a folded-in position. In this positionfor example the motor 2 can be synchronised with the rotation datameasured by the position pickup unit 12. By activating the motor 2 theshaft 1 then rotates by an angle α to a position 42. According to theinvention this rotation angle α can be detected both by the motor 2 andby the position pickup unit 12. In this context the motor 3 and theposition pickup unit 12 may be attached to the shaft so as to be inclose proximity to each other so that they monitor the same shaftregion. However, this is not mandatory. Instead, correspondingcalibration procedures can be undertaken, e.g. at defined conditions, sothat allocation of the motor measuring data to the position pickup unitdata can for example take place in the control unit 10.

Implementation of the invention is not limited to the preferredembodiments shown in the figure. Instead, a multitude of variants areimaginable which use the solution shown and the principle according tothe invention even in the case of fundamentally different embodiments.

In addition it should be pointed out that “comprising” does not excludeother elements or steps, and “a” or “one” does not exclude a pluralnumber. Furthermore, it should be pointed out that characteristics orsteps which have been described with reference to one of the aboveembodiments can also be used in combination with other characteristicsor steps of other embodiments described above. Reference characters inthe claims are not to be interpreted as limitations.

1. An aircraft having a device for determining the rotation angle of ashaft in the aircraft, the device comprising: a shaft designed foroperating a component, the component selected from the group consistingof a brake flap, a landing flap, a landing slat, a rudder, an aileronand an elevator, the shaft having a first region and a second region, amotor which rotates the shaft to detect first rotation datacorresponding to a first rotation angle of the first region of theshaft, the motor being designed to carry out said detection in anabsolute manner; a position pickup unit designed to detect secondrotation data corresponding to a second rotation angle of the secondregion of the shaft; a synchronization unit designed to synchronize thefirst rotation data with the second rotation data; and a control unitdesigned to provide a calibration procedure which determines a zeropoint of the motor on the basis of the second rotation data provided bythe position pickup unit.
 2. The aircraft of claim 1, wherein the motoris designed to transmit the first rotation data to the control unit;wherein the control unit is designed to control or regulate the rotationof the shaft on the basis of the transmitted first rotation data.
 3. Theaircraft of claim 1, wherein the motor is designed to transmit the firstrotation data to the control unit; wherein the position pickup unit isdesigned to transmit the second rotation data to the control unit;wherein the control unit is designed to control or regulate the rotationof the shaft on the basis of the transmitted first and second rotationdata.
 4. The aircraft of claim 3, wherein the control unit is designedcontrol or regulate the rotation of the shaft only on the basis of thetransmitted first rotation data when the transmitted second rotationdata is faulty or incomplete.
 5. The aircraft of claim 3, wherein thecontrol unit is designed to control or regulate the rotation of theshaft on the basis of the transmitted first and second rotation data,even if the transmitted second rotation data is faulty or incomplete. 6.An aircraft having a device for determining the rotation angle of ashaft in the aircraft, the device comprising: a shaft designed foroperating a component the component selected from the group consistingof a brake flap, a landing flap, a landing slat, a rudder, an aileronand an elevator, the shaft having a first region and a second region, amotor which rotates the shaft to detect first rotation datacorresponding to a first rotation angle of the first region of theshaft, the motor being designed to carry out said detection in anabsolute manner; a position pickup unit designed to detect secondrotation data corresponding to a second rotation angle of the secondregion of the shaft; a synchronization unit designed to synchronize thefirst rotation data with the second rotation data; and a control unitdesigned to detect and evaluate an incorrectness of the second rotationdata provided by the position pickup unit on the basis of the firstrotation data.
 7. The aircraft of claim 6, wherein the motor is designedto transmit the first rotation data to the control unit; wherein thecontrol unit is designed to control or regulate the rotation of theshaft on the basis of the transmitted first rotation data.
 8. Theaircraft of claim 6, wherein the motor is designed to transmit the firstrotation data to the control unit; wherein the position pickup unit isdesigned to transmit the second rotation data to the control unit;wherein the control unit is designed to control or regulate the rotationof the shaft on the basis of the transmitted first and second rotationdata.
 9. The aircraft of claim 8, wherein the control unit is designedcontrol or regulate the rotation of the shaft only on the basis of thetransmitted first rotation data when the transmitted second rotationdata is faulty or incomplete.
 10. The aircraft of claim 8, wherein thecontrol unit is designed to control or regulate the rotation of theshaft on the basis of the transmitted first and second rotation data,even if the transmitted second rotation data is faulty or incomplete.11. A method for determining the rotation angle of a shaft in anaircraft, comprising the steps of: rotating the shaft by a motor;detecting first rotation data that corresponds to a first rotation angleof a first region of the shaft by the motor in an absolute manner;detecting second rotation data that corresponds to a second rotationangle of a second region of the shaft by a position pickup unit;transmitting the first rotation data from the motor to a control unit;transmitting the second rotation data from the position pickup unit tothe control unit; determining a zero point of the motor on the basis ofthe second rotation data provided by the position pickup unit;synchronizing the first rotation data with the second rotation data; andcontrolling or regulating the rotation of the shaft on the basis of thetransmitted first and second rotation data by the control unit.
 12. Amethod for determining the rotation angle of a shaft in a aircraft,comprising the steps of: rotating the shaft by a motor; detecting firstrotation data that corresponds to a first rotation angle of a firstregion of the shaft by the motor in an absolute manner; detecting secondrotation data that corresponds to a second rotation angle of a secondregion of the shaft by a position pickup unit; transmitting the firstrotation data from the motor to a control unit; transmitting the secondrotation data from the position pickup unit to the control unit;detecting and evaluating an incorrectness of the second rotation dataprovided by the position pickup unit on the basis of the first rotationdata; synchronizing the first rotation data with the second rotationdata; and controlling or regulating the rotation of the shaft on thebasis of the transmitted first and second rotation data by the controlunit.